Keeping it short : A comparison of methods for brief picture presentation.

• Research has shown that backward masking is apowerful tool for studying unconscious mental processes.Whereas studies have traditionally presented stimuli usingcathode-ray tube (CRT) monitors or mechanical shutters togetherwith slide projectors, recent studies (mainly in functionalmagnetic resonance imaging, fMRI) have begun to use methodsbased on liquid crystal displays (LCDs) and thin-film transistor(TFT) technology. However, because of differences in technology,all methods may not be equally suited for masking. Whenmethods were compared for their accuracy in presenting picturesat short durations, LCD and TFT presentations had pooraccuracy, but shutter and CRT presentations had better accuracy.Because CRTs interfere with the imaging process in fMRI,we recommend the use of mechanical shutters. However, ourresults may not generally apply to all displays, so we adviseresearchers to validate the presentation parameters of theirdisplays. The procedure described here may be useful for thatpurpose.

Nyckelord

Consciousness/physiology

Humans

Perceptual Masking/*physiology

Time Factors

Visual Perception/*physiology

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)